My suggestion is to have them drop,for any hero, always at 10% and can roll up to 5 rolls - XP ,Credits, RIF, SIF, and orb pickup range. A perfect roll would have all 5. Sill slotted in the artifact slot.
This gives a use for a tech you already have with out breaking the game. What's an extra 40 % SIF or 40% RIF in the long run?